1. Field of the Invention
The invention relates to a semiconductor device manufacturing method, particularly to a packaging technology of a semiconductor device having penetrating electrodes.
2. Description of the Related Art
Conventionally, a packaging structure where a plurality of semiconductor chips having bump electrodes or penetrating electrodes are electrically and mechanically connected with each other through members made of low-melting metal such as solder is known.
FIGS. 8A and 8B are cross-sectional views for explaining a semiconductor device manufacturing method of a conventional art. As shown in FIG. 8A, a passivation film 51 is formed on a front surface of a first semiconductor chip 50. A plurality of bump electrodes 52 is formed on the front surface of the first semiconductor chip 50, and low-melting metallic members 53 are attached to tips of the bump electrodes 52.
On the other hand, a second semiconductor chip 60 is formed with a plurality of penetrating holes 61, and a penetrating electrode 62 made of metal such as Cu (copper) is embedded in each of the penetrating holes 61. The penetrating electrodes 62 are formed protruding from a back surface (upper surface in FIG. 8A) of the second semiconductor chip 60. The back surface of the second semiconductor chip 60 is covered with a passivation film 63 except a region formed with the penetrating electrodes 62.
The first semiconductor chip 50 and the second semiconductor chip 60 are disposed so that the bump electrodes 52 and the penetrating electrodes 62 face each other with keeping a predetermined space therebetween. The plurality of the bump electrodes 52 and the plurality of the penetrating electrodes 62 are disposed on the first semiconductor chip 50 and the second semiconductor chip 60 respectively, at micro-pitches of about 20 μm or less.
Next, as shown in FIG. 8B, the low-melting metallic members 53 are dissolved by heating, and the bump electrodes 52 and the penetrating electrodes 62 are connected through the dissolved low-melting metallic members 53. The dissolved low-melting metallic members 53 are hardened by cooling so that the bump electrodes 52 and the penetrating electrodes 62 are electrically and mechanically connected with each other through the low-melting metallic members 53.
FIGS. 9A and 9B are cross-sectional views for explaining a semiconductor device manufacturing method of other conventional art. In this conventional art, a plurality of semiconductor chips having bump electrodes or penetrating electrodes are resin-sealed simultaneously with electrical and mechanical connection thereof through low-melting metallic members.
As shown in FIG. 9A, an optimal amount of metal-active thermosetting resin 64 is attached to the back surface (surface facing the first semiconductor chip 50) of the second semiconductor chip 60. Then, as shown in FIG. 9B, the low-melting metallic members 53 are dissolved by heating to connect the bump electrodes 52 and the penetrating electrodes 62 through the dissolved low-melting metallic members 53, and simultaneously with this connection the thermosetting resin 64 is filled in a space between the first semiconductor chip 50 and the back surface of the second semiconductor chip 60.
A heating temperature is chosen and materials of the low-melting metallic members 53 and the thermosetting resin 64 are selected so as to harden the thermosetting resin 64 by heating simultaneously with dissolution of the low-melting metallic members 53. Therefore, the electrical and mechanical connection between the bump electrodes 52 and the penetrating electrodes 62 and resin-sealing thereof can be simultaneously realized.
Such technologies are disclosed in the Japanese Patent Application Publication No. Hei 10-12688.
In the conventional art shown in FIGS. 8A and 8B, however, if the low-melting metallic members 53 are oversupplied, a short circuit can occur between the adjacent electrodes as shown in FIG. 8B. The bump electrodes 52 and the penetrating electrodes 62 are disposed at micro-pitches of about 20 μm or less, so that it has been difficult to control a supply amount of the low-melting metallic members 53 properly.
Furthermore, in the other conventional art shown in FIGS. 9A and 9B, since the thermosetting resin 64 covers portions to be connected of the bump electrodes 52 and the penetrating electrodes 62 before connection, the thermosetting resin 64 can remain on the portions to be connected, i.e. surfaces to be connected of the bump electrodes 52 and the penetrating electrodes 62. FIG. 9B shows thermosetting resin 64A remaining on the portions to be connected. This reduces the electrical connection area of the bump electrodes 52 and the penetrating electrodes 62, so that resistance for connection increases or disconnection occurs to degrade characteristics of electrical connection.